拖拉机耕深模糊PID自动控制策略研究

Study on the Fuzzy PID Auto-control Strategy for Tractor Tillage Depth

为获得良好的拖拉机耕深均匀性、提高电液悬挂系统的控制精度,提出了一种耕深模糊PID自动控制策略。首先,介绍了系统的工作原理,并将加权系数应用于拖拉机力位综合控制的分析中,建立了系统各元件的数学模型;然后,根据系统的工作特性及耕深要求,设计了模糊PID控制器;最后,在Simulink中引入有限状态机模块,建立了电液悬挂系统力位综合控制的仿真模型。在相同阻力条件下,分别验证了加权系数取0、0.25、0.5、0.75、1时,控制器的响应效果并与PID控制器进行对比。仿真结果表明:提出的控制策略能更快、更精确地达到耕深设定值,满足了耕深均匀性的要求,为拖拉机电液悬挂系统多参数综合控制的设计提供了参考。

In order to get a better tillage depth uniformity of the tractor and improve the control precision of the electro-hydraulic hitch system,a fuzzy PID auto-control strategy for tractor plow depth is proposed. Firstly,the working principle of the system is introduced and the weighting coefficient is introduced into the modeling analysis of the force-position combined control. And the mathematical model of every part is established. Secondly,according to the working characteristics and tillage depth requirements of the system,a fuzzy PID controller is designed. Finally,the simulation model of electro-hydraulic hitch system is established,and the automatic closed-loop control is implemented. At the same time,under the same force condition,when the weighting coefficients were 0,0. 25,0. 5,0. 75 and 1,respectively,the response to the controller characteristics is verified and compared with the PID controller. The simulation results show that the proposed control strategy can meet the requirements of tillage depth uniformity and provide reference for the design of multiple parameter integrated control of tractor electro-hydraulic hitch system.